This works for me. In the folder that the .DATA folder is in, create a text only file with nothing in it that is the same name as the .DATA folder .enl (I use notepad in windows).
so if you have a library.DATA create a library.enl file in the same folder (not in the .DATA folder!)
Now double click on the library.enl file and it SHOULD open the .DATA folder if it hasn’t been corrupted.